FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_export.c
1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)vfs_subr.c 8.31 (Berkeley) 5/26/95
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/6.2/sys/kern/vfs_export.c 164286 2006-11-14 20:42:41Z cvs2svn $");
39
40 #include <sys/param.h>
41 #include <sys/dirent.h>
42 #include <sys/domain.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/mount.h>
48 #include <sys/mutex.h>
49 #include <sys/socket.h>
50 #include <sys/systm.h>
51 #include <sys/vnode.h>
52
53 #include <net/radix.h>
54
55 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
56
57 static void vfs_free_addrlist(struct netexport *nep);
58 static int vfs_free_netcred(struct radix_node *rn, void *w);
59 static int vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
60 struct export_args *argp);
61 static struct netcred *vfs_export_lookup(struct mount *, struct sockaddr *);
62
63 /*
64 * Network address lookup element
65 */
66 struct netcred {
67 struct radix_node netc_rnodes[2];
68 int netc_exflags;
69 struct ucred netc_anon;
70 };
71
72 /*
73 * Network export information
74 */
75 struct netexport {
76 struct netcred ne_defexported; /* Default export */
77 struct radix_node_head *ne_rtable[AF_MAX+1]; /* Individual exports */
78 };
79
80 /*
81 * Build hash lists of net addresses and hang them off the mount point.
82 * Called by ufs_mount() to set up the lists of export addresses.
83 */
84 static int
85 vfs_hang_addrlist(mp, nep, argp)
86 struct mount *mp;
87 struct netexport *nep;
88 struct export_args *argp;
89 {
90 register struct netcred *np;
91 register struct radix_node_head *rnh;
92 register int i;
93 struct radix_node *rn;
94 struct sockaddr *saddr, *smask = 0;
95 struct domain *dom;
96 int error;
97
98 /*
99 * XXX: This routine converts from a `struct xucred'
100 * (argp->ex_anon) to a `struct ucred' (np->netc_anon). This
101 * operation is questionable; for example, what should be done
102 * with fields like cr_uidinfo and cr_prison? Currently, this
103 * routine does not touch them (leaves them as NULL).
104 */
105 if (argp->ex_anon.cr_version != XUCRED_VERSION)
106 return (EINVAL);
107
108 if (argp->ex_addrlen == 0) {
109 if (mp->mnt_flag & MNT_DEFEXPORTED)
110 return (EPERM);
111 np = &nep->ne_defexported;
112 np->netc_exflags = argp->ex_flags;
113 bzero(&np->netc_anon, sizeof(np->netc_anon));
114 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
115 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
116 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
117 sizeof(np->netc_anon.cr_groups));
118 np->netc_anon.cr_ref = 1;
119 MNT_ILOCK(mp);
120 mp->mnt_flag |= MNT_DEFEXPORTED;
121 MNT_IUNLOCK(mp);
122 return (0);
123 }
124
125 #if MSIZE <= 256
126 if (argp->ex_addrlen > MLEN)
127 return (EINVAL);
128 #endif
129
130 i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
131 np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK | M_ZERO);
132 saddr = (struct sockaddr *) (np + 1);
133 if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen)))
134 goto out;
135 if (saddr->sa_family > AF_MAX) {
136 error = EINVAL;
137 goto out;
138 }
139 if (saddr->sa_len > argp->ex_addrlen)
140 saddr->sa_len = argp->ex_addrlen;
141 if (argp->ex_masklen) {
142 smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
143 error = copyin(argp->ex_mask, smask, argp->ex_masklen);
144 if (error)
145 goto out;
146 if (smask->sa_len > argp->ex_masklen)
147 smask->sa_len = argp->ex_masklen;
148 }
149 i = saddr->sa_family;
150 if ((rnh = nep->ne_rtable[i]) == NULL) {
151 /*
152 * Seems silly to initialize every AF when most are not used,
153 * do so on demand here
154 */
155 for (dom = domains; dom; dom = dom->dom_next)
156 if (dom->dom_family == i && dom->dom_rtattach) {
157 dom->dom_rtattach((void **) &nep->ne_rtable[i],
158 dom->dom_rtoffset);
159 break;
160 }
161 if ((rnh = nep->ne_rtable[i]) == NULL) {
162 error = ENOBUFS;
163 goto out;
164 }
165 }
166 RADIX_NODE_HEAD_LOCK(rnh);
167 rn = (*rnh->rnh_addaddr)(saddr, smask, rnh, np->netc_rnodes);
168 RADIX_NODE_HEAD_UNLOCK(rnh);
169 if (rn == NULL || np != (struct netcred *)rn) { /* already exists */
170 error = EPERM;
171 goto out;
172 }
173 np->netc_exflags = argp->ex_flags;
174 bzero(&np->netc_anon, sizeof(np->netc_anon));
175 np->netc_anon.cr_uid = argp->ex_anon.cr_uid;
176 np->netc_anon.cr_ngroups = argp->ex_anon.cr_ngroups;
177 bcopy(argp->ex_anon.cr_groups, np->netc_anon.cr_groups,
178 sizeof(np->netc_anon.cr_groups));
179 np->netc_anon.cr_ref = 1;
180 return (0);
181 out:
182 free(np, M_NETADDR);
183 return (error);
184 }
185
186 /* Helper for vfs_free_addrlist. */
187 /* ARGSUSED */
188 static int
189 vfs_free_netcred(rn, w)
190 struct radix_node *rn;
191 void *w;
192 {
193 register struct radix_node_head *rnh = (struct radix_node_head *) w;
194
195 (*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
196 free(rn, M_NETADDR);
197 return (0);
198 }
199
200 /*
201 * Free the net address hash lists that are hanging off the mount points.
202 */
203 static void
204 vfs_free_addrlist(nep)
205 struct netexport *nep;
206 {
207 register int i;
208 register struct radix_node_head *rnh;
209
210 for (i = 0; i <= AF_MAX; i++)
211 if ((rnh = nep->ne_rtable[i])) {
212 RADIX_NODE_HEAD_LOCK(rnh);
213 (*rnh->rnh_walktree) (rnh, vfs_free_netcred, rnh);
214 RADIX_NODE_HEAD_DESTROY(rnh);
215 free(rnh, M_RTABLE);
216 nep->ne_rtable[i] = NULL; /* not SMP safe XXX */
217 }
218 }
219
220 /*
221 * High level function to manipulate export options on a mount point
222 * and the passed in netexport.
223 * Struct export_args *argp is the variable used to twiddle options,
224 * the structure is described in sys/mount.h
225 */
226 int
227 vfs_export(mp, argp)
228 struct mount *mp;
229 struct export_args *argp;
230 {
231 struct netexport *nep;
232 int error;
233
234 nep = mp->mnt_export;
235 if (argp->ex_flags & MNT_DELEXPORT) {
236 if (nep == NULL)
237 return (ENOENT);
238 if (mp->mnt_flag & MNT_EXPUBLIC) {
239 vfs_setpublicfs(NULL, NULL, NULL);
240 MNT_ILOCK(mp);
241 mp->mnt_flag &= ~MNT_EXPUBLIC;
242 MNT_IUNLOCK(mp);
243 }
244 vfs_free_addrlist(nep);
245 mp->mnt_export = NULL;
246 free(nep, M_MOUNT);
247 nep = NULL;
248 MNT_ILOCK(mp);
249 mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
250 MNT_IUNLOCK(mp);
251 }
252 if (argp->ex_flags & MNT_EXPORTED) {
253 if (nep == NULL) {
254 nep = malloc(sizeof(struct netexport), M_MOUNT, M_WAITOK | M_ZERO);
255 mp->mnt_export = nep;
256 }
257 if (argp->ex_flags & MNT_EXPUBLIC) {
258 if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
259 return (error);
260 MNT_ILOCK(mp);
261 mp->mnt_flag |= MNT_EXPUBLIC;
262 MNT_IUNLOCK(mp);
263 }
264 if ((error = vfs_hang_addrlist(mp, nep, argp)))
265 return (error);
266 MNT_ILOCK(mp);
267 mp->mnt_flag |= MNT_EXPORTED;
268 MNT_IUNLOCK(mp);
269 }
270 return (0);
271 }
272
273 /*
274 * Set the publicly exported filesystem (WebNFS). Currently, only
275 * one public filesystem is possible in the spec (RFC 2054 and 2055)
276 */
277 int
278 vfs_setpublicfs(mp, nep, argp)
279 struct mount *mp;
280 struct netexport *nep;
281 struct export_args *argp;
282 {
283 int error;
284 struct vnode *rvp;
285 char *cp;
286
287 /*
288 * mp == NULL -> invalidate the current info, the FS is
289 * no longer exported. May be called from either vfs_export
290 * or unmount, so check if it hasn't already been done.
291 */
292 if (mp == NULL) {
293 if (nfs_pub.np_valid) {
294 nfs_pub.np_valid = 0;
295 if (nfs_pub.np_index != NULL) {
296 FREE(nfs_pub.np_index, M_TEMP);
297 nfs_pub.np_index = NULL;
298 }
299 }
300 return (0);
301 }
302
303 /*
304 * Only one allowed at a time.
305 */
306 if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
307 return (EBUSY);
308
309 /*
310 * Get real filehandle for root of exported FS.
311 */
312 bzero(&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
313 nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
314
315 if ((error = VFS_ROOT(mp, LK_EXCLUSIVE, &rvp, curthread /* XXX */)))
316 return (error);
317
318 if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
319 return (error);
320
321 vput(rvp);
322
323 /*
324 * If an indexfile was specified, pull it in.
325 */
326 if (argp->ex_indexfile != NULL) {
327 MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
328 M_WAITOK);
329 error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
330 MAXNAMLEN, (size_t *)0);
331 if (!error) {
332 /*
333 * Check for illegal filenames.
334 */
335 for (cp = nfs_pub.np_index; *cp; cp++) {
336 if (*cp == '/') {
337 error = EINVAL;
338 break;
339 }
340 }
341 }
342 if (error) {
343 FREE(nfs_pub.np_index, M_TEMP);
344 return (error);
345 }
346 }
347
348 nfs_pub.np_mount = mp;
349 nfs_pub.np_valid = 1;
350 return (0);
351 }
352
353 /*
354 * Used by the filesystems to determine if a given network address
355 * (passed in 'nam') is present in thier exports list, returns a pointer
356 * to struct netcred so that the filesystem can examine it for
357 * access rights (read/write/etc).
358 */
359 static struct netcred *
360 vfs_export_lookup(struct mount *mp, struct sockaddr *nam)
361 {
362 struct netexport *nep;
363 register struct netcred *np;
364 register struct radix_node_head *rnh;
365 struct sockaddr *saddr;
366
367 nep = mp->mnt_export;
368 if (nep == NULL)
369 return (NULL);
370 np = NULL;
371 if (mp->mnt_flag & MNT_EXPORTED) {
372 /*
373 * Lookup in the export list first.
374 */
375 if (nam != NULL) {
376 saddr = nam;
377 rnh = nep->ne_rtable[saddr->sa_family];
378 if (rnh != NULL) {
379 RADIX_NODE_HEAD_LOCK(rnh);
380 np = (struct netcred *)
381 (*rnh->rnh_matchaddr)(saddr, rnh);
382 RADIX_NODE_HEAD_UNLOCK(rnh);
383 if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
384 np = NULL;
385 }
386 }
387 /*
388 * If no address match, use the default if it exists.
389 */
390 if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
391 np = &nep->ne_defexported;
392 }
393 return (np);
394 }
395
396 /*
397 * XXX: This comment comes from the deprecated ufs_check_export()
398 * XXX: and may not entirely apply, but lacking something better:
399 * This is the generic part of fhtovp called after the underlying
400 * filesystem has validated the file handle.
401 *
402 * Verify that a host should have access to a filesystem.
403 */
404
405 int
406 vfs_stdcheckexp(mp, nam, extflagsp, credanonp)
407 struct mount *mp;
408 struct sockaddr *nam;
409 int *extflagsp;
410 struct ucred **credanonp;
411 {
412 struct netcred *np;
413
414 np = vfs_export_lookup(mp, nam);
415 if (np == NULL)
416 return (EACCES);
417 *extflagsp = np->netc_exflags;
418 *credanonp = &np->netc_anon;
419 return (0);
420 }
421
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